7 ms·

Digital Wood Joints

141 points by montgomery_r 2y ago

deleted 2y ago
[deleted]
uticus 2y ago
the images are great, but need more info about strengths & weaknesses of each type
geekodour 2y ago
think the site suffered a hug, not opening for me ;(
- WillAdams 2y ago
  I believe it's the same as: http://winterdienst.info/50-digital-wood-joints-by-jochen-gros/ http://winterdienst.info/50-digital-wood-joints-by-jochen-gr... (which is the original site and which would be better to use/link to)
8ig8 2y ago
Charles Hayward [1] has a great book on the topic: Woodwork Joints https://archive.org/details/woodworkjointski0000hayw_k7x4 https://archive.org/details/woodworkjointski0000hayw_k7x4 Hayward discusses not only the joints, but techniques for cutting them with hand tools. There are plenty of used copies out there. Hayward has many other useful books. 1: https://en.wikipedia.org/wiki/Charles_H._Hayward https://en.wikipedia.org/wiki/Charles_H._Hayward
lemma_peculiar 2y ago
this is an excellent reference - not only for computer-controlled wood processing, but also for digital fabrication. When trying to create pieces made of plastics, you will sometimes need a strong joint, and wood-working is the perfect place to look
jefb 2y ago
Very cool graphic. However emphasizing the juxtaposition between pictures of wood joints on the internet and actual real-life wood joints with the phrase "digital" is a bit perplexing.
- e28eta 2y ago
  I think “digital wood joints” emphasizes that they’re meant to be cut with a CNC, and thus aren’t the traditional wood joints that have been taught for centuries. I don’t think it has anything to do with the fact that this content is available digitally.
  - michaelt 2y ago
    Honestly I thought they were trying to make a cute pun by calling finger joints 'digital' Your interpretation is more likely, though. And explains why so many of the joints are weird and look like they'd leave gaps...
affgrff2 2y ago
Offenbach also hosts a relatively large Japan festival (in Germany). Wood joinery, at least in my mind, is a very Japanese craft. I wonder if this is by accident.
- mauvehaus 2y ago
  There are a couple of Japanese joinery books out there. One that I've read gives the reasoning for all of the joints in the Japanese tradition for joining two boards end to end (thereby creating a longer board, in effect) is that the timber available for building in Japan doesn't come in long, straight lengths. I can't tell you if that's true or not, but I have a hard time seeing folks putting so much work into developing such joints without a pressing need for them.
- jcl 2y ago
  There’s a wonderful little carpentry museum in Kobe, highly recommended: https://www.dougukan.jp/exhibition?lang=en https://www.dougukan.jp/exhibition?lang=en It focuses a lot on the evolution of precise woodworking tools, like saws and planes. They also had examples of complex joints, made without nails or glue.
  - montgomery_r 2y ago
    Lovely!
mauvehaus 2y ago
These are all designed for CNC cutting, and appear to be intended as one-sided jobs worked with the face of the board down. That is generally the simplest way to hold a board on a CNC. I would caution anyone thinking of doing joinery this way to consider whether it's actually suitable for the application. I was at a coffee shop once where absolutely every chair in the place was starting to fall apart. The reason was that the joinery was all some variation of half-lap, which doesn't constrain the movement of the pieces in all of the directions that matter. Once the glue failed, the chairs started coming apart. I would also add that the corner joints meant to replace dovetails or a box/beehive joint are unsightly with all the required dogboning and will not improve aesthetically with the addition of glue. I would further point out that there are already quick ways to cut dovetails or box joints with a router quickly and efficiently. It would be hard to convince me that there's a truly useful role for cutting an uglier version of a box joint on a CNC. Source: am a furniture maker who does some CNC work.
- e28eta 2y ago
  I wonder how much of the simplicity is due to the fact it was created in 2004. I don’t have a good feeling for how quickly things progressed over the last 20 years
  - mauvehaus 2y ago
    I wasn't in the trade in 2004, so some of this is a bit speculative: It looks like everything on the poster is made to be cut on a 3-axis machine. Stepping up to five-axis is a huge leap in cost at present, and surely was then as well. Tooling has likely improved in availability and cost since 2004 as well. Automatic tool changers have probably also become more affordable, but just like going to five-axis, you're getting into a whole different class of machine once you start talking about adding that. Some of the reasons to cut stuff single-sided on the flat are unchanged by any of that though. It still costs you precision (and time) to flip a workpiece over, and you're going to have issues if you don't have good consistency with your material thickness if you need to reference your Z axis to the material surface rather than the bed surface. Working an end of a long piece remains a pain in the ass for fixturing that involves a hole in your machine bed, and possibly the floor as well. Tenoning a bed rail, for instance, is inconvenient however you do it. All of my CNC experience is on a three-axis machine, five-axis gets you a lot of flexibility that most places won't have unless CNC work is their primary focus, or at least core to their workflow. I've seen a shop that builds high-end windows with a large five axis machine. I have no concerns about the durability of their products, it's just that most people don't have access to that kind of capability.
deleted 2y ago
[deleted]
e28eta 2y ago
Based only on the pics in the “poster”, it looks like a lot of the joints in the second half have visible gaps. I think I would have expected more emphasis on joints that can be cut with the CNC’s round cutter, but which also come together cleanly. Also, an over abundance of lengthening / scarf type joints, more than the typical woodworker would use, IMO.
chiffre01 2y ago
I'd like to think we're at a place where CNC machines are cheap and accessible enough that clever tricks or new tools are just around the corner to overcome some of the inherent issues of making basic wood joints on a CNC router. To me, these look like a stepping stone to something better. They're all intended to be used with a flat-shaped endmill, and all probably have strength and aesthetic issues. One solution is using different router bit shapes in combination with traditional techniques, but this is more labor-intensive.
- jeffffff 2y ago
  we're not really close, for two reasons: 1) programming takes a long time, and it only makes sense to take the time to do it if you're making a bunch of copies of something. this is something that could be improved with better software and ux - if cad programs made it easy to just drag and drop joints from a joint library into your model then this would be a different story. a hardware+software solution could also work here, something like a cnc version of https://www.woodpeck.com/multi-router-group.html https://www.woodpeck.com/multi-router-group.html where the software makes it easy to scale the templates to your work piece. 2) setup takes a long time on the affordable machines. every time you change bits you have to recalibrate. positioning the work piece on the table and clamping/taping it down takes a lot of time. if you have to flip the work piece over then that takes even longer and positioning is even more critical, and programming is more complicated as well. regardless of whether your designs require cutting on one or both sides, you have to program tabs into your design so the router doesn't cut all the way through (or else the piece will move and the router will screw it up), and then you have to go back and cut the pieces out the rest of the way manually and trim off the tabs with a flush trim router bit. the high end production quality machines mitigate a lot of these issues, but now you are talking about a machine that costs at least $100,000 and takes up a whole room.
  - deleted 2y ago
    [deleted]
  - WillAdams 2y ago
    I've been working on the software end of things: http://tug.org/TUGboat/tb40-2/tb125adams-3d.pdf http://tug.org/TUGboat/tb40-2/tb125adams-3d.pdf and https://community.carbide3d.com/t/a-different-sort-of-box/36882 https://community.carbide3d.com/t/a-different-sort-of-box/36... and for more see: https://willadams.gitbook.io/design-into-3d/programming https://willadams.gitbook.io/design-into-3d/programming
OJFord 2y ago
Meh, Matthias Wandel's still going to beat you on speed (and quite possibly strength) with his homemade pantorouter or box joint jig. As much as I like nice joint design, I think a lot of that aesthetic beauty comes from when it's not machinable (or not traditionally anyway, iirc the pantorouter can make some pretty tight dovetails - because of the orientation vs. trying to route them 'normally'). It's not how fancy and curvey can it look, it's how intricate and fine the detail. Chunky dovetails don't look better than box joints in my opinion.
- WillAdams 2y ago
  I would argue that it shouldn't be necessary to see joinery at all --- I find full-blind dovetails far more impressive and aesthetically pleasing.
WillAdams 2y ago
I've been working on this sort of thing for a while. For a Japanese spin on this see Tsugite: http://ma-la.com/Tsugite_UIST20.pdf http://ma-la.com/Tsugite_UIST20.pdf which I worked through at: https://community.carbide3d.com/t/a-study-of-joinery/28492 https://community.carbide3d.com/t/a-study-of-joinery/28492 Traditional joints (box, dovetails, or obscure variations such as Knapp (cove and pin)) require a vertical fixture and 3 setups (at a minimum) --- cut parts to length and machine internal features, mount four board and cut joints in 2 corners, flip boards (with correct orientation) and cut other two corners. Rabbet joints are simpler --- so simple that they were covered in a video as "The Simple Box": https://www.youtube.com/watch?v=V93xDM3lXsM https://www.youtube.com/watch?v=V93xDM3lXsM (ob. discl., I work for Carbide 3D) There have been a number of programs developed for joinery. A current commercial option is: http://www.g-forcecnc.com/jointcam.html http://www.g-forcecnc.com/jointcam.html (but it requires a vertical fixture) One commercial option became freely available: https://fabrikisto.com/tailmaker-software/ https://fabrikisto.com/tailmaker-software/ and ingeniously has an option where a 30 degree V endmill is used, but to cut boards held at a 15 degree angle, affording a 90 degree cut with a great deal of control and flexibility --- this can multiply setups to 9. A variation I've been experimenting with is full-blind box joints: https://community.carbide3d.com/t/full-blind-box-joints-in-carbide-create/53329 https://community.carbide3d.com/t/full-blind-box-joints-in-c... They're reasonably easily drawn up, though they do have some rather specific tooling requirements (a narrow 90 degree V endmill, a square tool of that or smaller diameter, and to make things easier, a large V endmill) One test project was so tight that after putting it together for a dry-fit before gluing I was unable to get it apart: https://cutrocket.com/p/63781eaf9822f/ https://cutrocket.com/p/63781eaf9822f/ I've been working on a programming system to make this sort of thing a bit easier: https://github.com/WillAdams/gcodepreview https://github.com/WillAdams/gcodepreview and have some sketched out joints which I've not been able to make using existing CAM tools which I hope I'll be able to do using this system (if anyone could recommend books on conic sections, I'd be grateful --- that's where I got bogged down last time).
KaiserPro 2y ago
I wish I could find the clip now, but with the advent of practical router bits with pantographs, there was a fashion in the late 1800s to replace dovetail joints with dowel and C type joints. They were really hard to make fast by hand, but easy to do with machines. They could be made to higher tolerances, and had more surface area, and I assume were more reliable to make/hold draws together. These are very similar to the idea here. EDIT: thankyou to mikey_p and WillAdams who pointed out the joint I was looking for was the Knapp Joint: https://www.finewoodworking.com/2018/09/26/history-cove-pin-joint https://www.finewoodworking.com/2018/09/26/history-cove-pin-...
- WillAdams 2y ago
  Probably you were thinking of "Knapp joints" (cove and pin) which had a currency of a decade or so (their presence is used to date furniture), but which were replaced by machine cut dovetails. A CNC router affords a lot of new possibilities, e.g., this box which has an integrated lid: https://community.carbide3d.com/t/as-funny-as-a-3-dollar-box/43013/18 https://community.carbide3d.com/t/as-funny-as-a-3-dollar-box...
- mikey_p 2y ago
  You're thinking of the Knapp joint which were sometimes called dovetails. The pantograph router version is a modern recreation of how the original was made. This video has some explanation of the new method and why they were originally popular in the first place (mostly limitations of available machines): https://www.youtube.com/watch?v=MlJjsvph3r8&ab_channel=Matthiasrandomstuff https://www.youtube.com/watch?v=MlJjsvph3r8&ab_channel=Matth...
  - KaiserPro 2y ago
    Excellent thank you for the video!
Animats 2y ago
Nice. But the link is to a clickbait site with dark patterns for the privacy policy. The real article is here.[1] Somebody should run these through a finite-element package to compute their strength. Some of those look fragile. [1] http://winterdienst.info/50-digital-wood-joints-by-jochen-gros/ http://winterdienst.info/50-digital-wood-joints-by-jochen-gr...
- btbuildem 2y ago
  Precisely! They look pretty but there's a reason (beyond tools and skills) some of these have never been seen in practice. Would be super interesting to see stress analysis on these.
Duanemclemore 2y ago
This is phenomenal. I wish I had it to share with a student I worked with last year. Even without this, he came to similar realizations and explored similar territory with significant results.[0] He began by comparing and contrasting traditional Japanese joinery with CNC milled joints. He realized that the critical difference was that Japanese carpentry joints are almost always entirely squared off (due to the flat saw and chisels). Yet the inside corners created with CNC were always rounded. So he let this critical difference be the animating concept of the project. So if you enjoy this, you might enjoy Luke's work too! [0]https://issuu.com/lukemurrayarc/docs/portfolio_2023 https://issuu.com/lukemurrayarc/docs/portfolio_2023 starting at page 26-27.
- stcredzero 2y ago
  Here is what immediately comes to my mind. - Figure out a way to parameterize joints - Create an automated evaluator that uses finite element analysis - Evolve joints with a genetic algorithm
  - WhatsTheBigIdea 2y ago
    Oooo... that's a great idea! I would love to see the output of that project!
  - WillAdams 2y ago
    You left out one step/criteria: - constrain joints so that they can be cut with a tool on a CNC with the material secured on the machine in a convenient fashion in a reasonable period of time which is something I've been working on.
    - stcredzero 2y ago
      constrain joints so that they can be cut with a tool on a CNC with the material secured on the machine in a convenient fashion in a reasonable period of time Could one make that a part of the evaluator/fitness function?
TheRealNGenius 2y ago
[dead]
btbuildem 2y ago
Interesting idea, using the strengths of the tooling to expand how joinery can look. Some of these are photos; looks like they made actual wood examples of some of these joints. What is really missing for me here is complete pieces, utilizing some or many of these new joints throughout. Are they practical? Do they look good as part of a larger whole? Even 3D renders would be a good start, if not an actual physical piece.
netsharc 2y ago
Off-topic, but that's a giant fuck you of a cookie popup... it's got 3 options of "high/medium/custom data privacy", a duration of how long I would like to keep those settings (just like those nagware popups of "Try OneDrive/Teams/[whatever fucking bullshit] now!" with no option for "Get off my OS!", only "Remind me later"), a customize toggler that makes it even larger to have more settings. Someone programmed this to frustrate the user with " And the description for the 3 options is contradictory. Above them it says, "Select a Data Access Level", but selecting "High", the description is "Highest level of privacy"... So what does it do, give the advertisers a high level of access, or give me a high level of privacy?
- WillAdams 2y ago
  Yep, such links should be re-written to the original source, in this case: http://winterdienst.info/50-digital-wood-joints-by-jochen-gros/ http://winterdienst.info/50-digital-wood-joints-by-jochen-gr...
MarkMarine 2y ago
Most of these are basically impossible to cut without CNC. Once you’ve embraced CNC as your joint method, why wood is the next question. If you want to learn wood joints, learn mortise and tenon, dovetails, dowels or floating tenons, and nailed/screwed joints. Some extra love for biscuit miter joints but really that is all the main ones people use.

Digital Wood Joints

141 points by montgomery_r 2y ago

deleted 2y ago

[deleted]

uticus 2y ago

the images are great, but need more info about strengths & weaknesses of each type

geekodour 2y ago

think the site suffered a hug, not opening for me ;(

WillAdams 2y ago
I believe it's the same as: http://winterdienst.info/50-digital-wood-joints-by-jochen-gros/ http://winterdienst.info/50-digital-wood-joints-by-jochen-gr... (which is the original site and which would be better to use/link to)

8ig8 2y ago

Charles Hayward [1] has a great book on the topic: Woodwork Joints https://archive.org/details/woodworkjointski0000hayw_k7x4 https://archive.org/details/woodworkjointski0000hayw_k7x4 Hayward discusses not only the joints, but techniques for cutting them with hand tools. There are plenty of used copies out there. Hayward has many other useful books. 1: https://en.wikipedia.org/wiki/Charles_H._Hayward https://en.wikipedia.org/wiki/Charles_H._Hayward

lemma_peculiar 2y ago

this is an excellent reference - not only for computer-controlled wood processing, but also for digital fabrication. When trying to create pieces made of plastics, you will sometimes need a strong joint, and wood-working is the perfect place to look

jefb 2y ago

Very cool graphic. However emphasizing the juxtaposition between pictures of wood joints on the internet and actual real-life wood joints with the phrase "digital" is a bit perplexing.

e28eta 2y ago
I think “digital wood joints” emphasizes that they’re meant to be cut with a CNC, and thus aren’t the traditional wood joints that have been taught for centuries. I don’t think it has anything to do with the fact that this content is available digitally.
- michaelt 2y ago
  Honestly I thought they were trying to make a cute pun by calling finger joints 'digital' Your interpretation is more likely, though. And explains why so many of the joints are weird and look like they'd leave gaps...

affgrff2 2y ago

Offenbach also hosts a relatively large Japan festival (in Germany). Wood joinery, at least in my mind, is a very Japanese craft. I wonder if this is by accident.

mauvehaus 2y ago
There are a couple of Japanese joinery books out there. One that I've read gives the reasoning for all of the joints in the Japanese tradition for joining two boards end to end (thereby creating a longer board, in effect) is that the timber available for building in Japan doesn't come in long, straight lengths. I can't tell you if that's true or not, but I have a hard time seeing folks putting so much work into developing such joints without a pressing need for them.
jcl 2y ago
There’s a wonderful little carpentry museum in Kobe, highly recommended: https://www.dougukan.jp/exhibition?lang=en https://www.dougukan.jp/exhibition?lang=en It focuses a lot on the evolution of precise woodworking tools, like saws and planes. They also had examples of complex joints, made without nails or glue.
- montgomery_r 2y ago
  Lovely!

mauvehaus 2y ago

These are all designed for CNC cutting, and appear to be intended as one-sided jobs worked with the face of the board down. That is generally the simplest way to hold a board on a CNC. I would caution anyone thinking of doing joinery this way to consider whether it's actually suitable for the application. I was at a coffee shop once where absolutely every chair in the place was starting to fall apart. The reason was that the joinery was all some variation of half-lap, which doesn't constrain the movement of the pieces in all of the directions that matter. Once the glue failed, the chairs started coming apart. I would also add that the corner joints meant to replace dovetails or a box/beehive joint are unsightly with all the required dogboning and will not improve aesthetically with the addition of glue. I would further point out that there are already quick ways to cut dovetails or box joints with a router quickly and efficiently. It would be hard to convince me that there's a truly useful role for cutting an uglier version of a box joint on a CNC. Source: am a furniture maker who does some CNC work.

e28eta 2y ago
I wonder how much of the simplicity is due to the fact it was created in 2004. I don’t have a good feeling for how quickly things progressed over the last 20 years
- mauvehaus 2y ago
  I wasn't in the trade in 2004, so some of this is a bit speculative: It looks like everything on the poster is made to be cut on a 3-axis machine. Stepping up to five-axis is a huge leap in cost at present, and surely was then as well. Tooling has likely improved in availability and cost since 2004 as well. Automatic tool changers have probably also become more affordable, but just like going to five-axis, you're getting into a whole different class of machine once you start talking about adding that. Some of the reasons to cut stuff single-sided on the flat are unchanged by any of that though. It still costs you precision (and time) to flip a workpiece over, and you're going to have issues if you don't have good consistency with your material thickness if you need to reference your Z axis to the material surface rather than the bed surface. Working an end of a long piece remains a pain in the ass for fixturing that involves a hole in your machine bed, and possibly the floor as well. Tenoning a bed rail, for instance, is inconvenient however you do it. All of my CNC experience is on a three-axis machine, five-axis gets you a lot of flexibility that most places won't have unless CNC work is their primary focus, or at least core to their workflow. I've seen a shop that builds high-end windows with a large five axis machine. I have no concerns about the durability of their products, it's just that most people don't have access to that kind of capability.

deleted 2y ago

[deleted]

e28eta 2y ago

Based only on the pics in the “poster”, it looks like a lot of the joints in the second half have visible gaps. I think I would have expected more emphasis on joints that can be cut with the CNC’s round cutter, but which also come together cleanly. Also, an over abundance of lengthening / scarf type joints, more than the typical woodworker would use, IMO.

chiffre01 2y ago

I'd like to think we're at a place where CNC machines are cheap and accessible enough that clever tricks or new tools are just around the corner to overcome some of the inherent issues of making basic wood joints on a CNC router. To me, these look like a stepping stone to something better. They're all intended to be used with a flat-shaped endmill, and all probably have strength and aesthetic issues. One solution is using different router bit shapes in combination with traditional techniques, but this is more labor-intensive.

jeffffff 2y ago
we're not really close, for two reasons: 1) programming takes a long time, and it only makes sense to take the time to do it if you're making a bunch of copies of something. this is something that could be improved with better software and ux - if cad programs made it easy to just drag and drop joints from a joint library into your model then this would be a different story. a hardware+software solution could also work here, something like a cnc version of https://www.woodpeck.com/multi-router-group.html https://www.woodpeck.com/multi-router-group.html where the software makes it easy to scale the templates to your work piece. 2) setup takes a long time on the affordable machines. every time you change bits you have to recalibrate. positioning the work piece on the table and clamping/taping it down takes a lot of time. if you have to flip the work piece over then that takes even longer and positioning is even more critical, and programming is more complicated as well. regardless of whether your designs require cutting on one or both sides, you have to program tabs into your design so the router doesn't cut all the way through (or else the piece will move and the router will screw it up), and then you have to go back and cut the pieces out the rest of the way manually and trim off the tabs with a flush trim router bit. the high end production quality machines mitigate a lot of these issues, but now you are talking about a machine that costs at least $100,000 and takes up a whole room.
- deleted 2y ago
  [deleted]
- WillAdams 2y ago
  I've been working on the software end of things: http://tug.org/TUGboat/tb40-2/tb125adams-3d.pdf http://tug.org/TUGboat/tb40-2/tb125adams-3d.pdf and https://community.carbide3d.com/t/a-different-sort-of-box/36882 https://community.carbide3d.com/t/a-different-sort-of-box/36... and for more see: https://willadams.gitbook.io/design-into-3d/programming https://willadams.gitbook.io/design-into-3d/programming

OJFord 2y ago

Meh, Matthias Wandel's still going to beat you on speed (and quite possibly strength) with his homemade pantorouter or box joint jig. As much as I like nice joint design, I think a lot of that aesthetic beauty comes from when it's not machinable (or not traditionally anyway, iirc the pantorouter can make some pretty tight dovetails - because of the orientation vs. trying to route them 'normally'). It's not how fancy and curvey can it look, it's how intricate and fine the detail. Chunky dovetails don't look better than box joints in my opinion.

WillAdams 2y ago
I would argue that it shouldn't be necessary to see joinery at all --- I find full-blind dovetails far more impressive and aesthetically pleasing.

WillAdams 2y ago

I've been working on this sort of thing for a while. For a Japanese spin on this see Tsugite: http://ma-la.com/Tsugite_UIST20.pdf http://ma-la.com/Tsugite_UIST20.pdf which I worked through at: https://community.carbide3d.com/t/a-study-of-joinery/28492 https://community.carbide3d.com/t/a-study-of-joinery/28492 Traditional joints (box, dovetails, or obscure variations such as Knapp (cove and pin)) require a vertical fixture and 3 setups (at a minimum) --- cut parts to length and machine internal features, mount four board and cut joints in 2 corners, flip boards (with correct orientation) and cut other two corners. Rabbet joints are simpler --- so simple that they were covered in a video as "The Simple Box": https://www.youtube.com/watch?v=V93xDM3lXsM https://www.youtube.com/watch?v=V93xDM3lXsM (ob. discl., I work for Carbide 3D) There have been a number of programs developed for joinery. A current commercial option is: http://www.g-forcecnc.com/jointcam.html http://www.g-forcecnc.com/jointcam.html (but it requires a vertical fixture) One commercial option became freely available: https://fabrikisto.com/tailmaker-software/ https://fabrikisto.com/tailmaker-software/ and ingeniously has an option where a 30 degree V endmill is used, but to cut boards held at a 15 degree angle, affording a 90 degree cut with a great deal of control and flexibility --- this can multiply setups to 9. A variation I've been experimenting with is full-blind box joints: https://community.carbide3d.com/t/full-blind-box-joints-in-carbide-create/53329 https://community.carbide3d.com/t/full-blind-box-joints-in-c... They're reasonably easily drawn up, though they do have some rather specific tooling requirements (a narrow 90 degree V endmill, a square tool of that or smaller diameter, and to make things easier, a large V endmill) One test project was so tight that after putting it together for a dry-fit before gluing I was unable to get it apart: https://cutrocket.com/p/63781eaf9822f/ https://cutrocket.com/p/63781eaf9822f/ I've been working on a programming system to make this sort of thing a bit easier: https://github.com/WillAdams/gcodepreview https://github.com/WillAdams/gcodepreview and have some sketched out joints which I've not been able to make using existing CAM tools which I hope I'll be able to do using this system (if anyone could recommend books on conic sections, I'd be grateful --- that's where I got bogged down last time).

KaiserPro 2y ago

I wish I could find the clip now, but with the advent of practical router bits with pantographs, there was a fashion in the late 1800s to replace dovetail joints with dowel and C type joints. They were really hard to make fast by hand, but easy to do with machines. They could be made to higher tolerances, and had more surface area, and I assume were more reliable to make/hold draws together. These are very similar to the idea here. EDIT: thankyou to mikey_p and WillAdams who pointed out the joint I was looking for was the Knapp Joint: https://www.finewoodworking.com/2018/09/26/history-cove-pin-joint https://www.finewoodworking.com/2018/09/26/history-cove-pin-...

WillAdams 2y ago
Probably you were thinking of "Knapp joints" (cove and pin) which had a currency of a decade or so (their presence is used to date furniture), but which were replaced by machine cut dovetails. A CNC router affords a lot of new possibilities, e.g., this box which has an integrated lid: https://community.carbide3d.com/t/as-funny-as-a-3-dollar-box/43013/18 https://community.carbide3d.com/t/as-funny-as-a-3-dollar-box...
mikey_p 2y ago
You're thinking of the Knapp joint which were sometimes called dovetails. The pantograph router version is a modern recreation of how the original was made. This video has some explanation of the new method and why they were originally popular in the first place (mostly limitations of available machines): https://www.youtube.com/watch?v=MlJjsvph3r8&ab_channel=Matthiasrandomstuff https://www.youtube.com/watch?v=MlJjsvph3r8&ab_channel=Matth...
- KaiserPro 2y ago
  Excellent thank you for the video!

Animats 2y ago

Nice. But the link is to a clickbait site with dark patterns for the privacy policy. The real article is here.[1] Somebody should run these through a finite-element package to compute their strength. Some of those look fragile. [1] http://winterdienst.info/50-digital-wood-joints-by-jochen-gros/ http://winterdienst.info/50-digital-wood-joints-by-jochen-gr...

btbuildem 2y ago
Precisely! They look pretty but there's a reason (beyond tools and skills) some of these have never been seen in practice. Would be super interesting to see stress analysis on these.

Duanemclemore 2y ago

This is phenomenal. I wish I had it to share with a student I worked with last year. Even without this, he came to similar realizations and explored similar territory with significant results.[0] He began by comparing and contrasting traditional Japanese joinery with CNC milled joints. He realized that the critical difference was that Japanese carpentry joints are almost always entirely squared off (due to the flat saw and chisels). Yet the inside corners created with CNC were always rounded. So he let this critical difference be the animating concept of the project. So if you enjoy this, you might enjoy Luke's work too! [0]https://issuu.com/lukemurrayarc/docs/portfolio_2023 https://issuu.com/lukemurrayarc/docs/portfolio_2023 starting at page 26-27.

stcredzero 2y ago
Here is what immediately comes to my mind. - Figure out a way to parameterize joints - Create an automated evaluator that uses finite element analysis - Evolve joints with a genetic algorithm
- WhatsTheBigIdea 2y ago
  Oooo... that's a great idea! I would love to see the output of that project!
- WillAdams 2y ago
  You left out one step/criteria: - constrain joints so that they can be cut with a tool on a CNC with the material secured on the machine in a convenient fashion in a reasonable period of time which is something I've been working on.
  - stcredzero 2y ago
    constrain joints so that they can be cut with a tool on a CNC with the material secured on the machine in a convenient fashion in a reasonable period of time Could one make that a part of the evaluator/fitness function?

TheRealNGenius 2y ago

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btbuildem 2y ago

Interesting idea, using the strengths of the tooling to expand how joinery can look. Some of these are photos; looks like they made actual wood examples of some of these joints. What is really missing for me here is complete pieces, utilizing some or many of these new joints throughout. Are they practical? Do they look good as part of a larger whole? Even 3D renders would be a good start, if not an actual physical piece.

netsharc 2y ago

Off-topic, but that's a giant fuck you of a cookie popup... it's got 3 options of "high/medium/custom data privacy", a duration of how long I would like to keep those settings (just like those nagware popups of "Try OneDrive/Teams/[whatever fucking bullshit] now!" with no option for "Get off my OS!", only "Remind me later"), a customize toggler that makes it even larger to have more settings. Someone programmed this to frustrate the user with " And the description for the 3 options is contradictory. Above them it says, "Select a Data Access Level", but selecting "High", the description is "Highest level of privacy"... So what does it do, give the advertisers a high level of access, or give me a high level of privacy?

WillAdams 2y ago
Yep, such links should be re-written to the original source, in this case: http://winterdienst.info/50-digital-wood-joints-by-jochen-gros/ http://winterdienst.info/50-digital-wood-joints-by-jochen-gr...

MarkMarine 2y ago

Most of these are basically impossible to cut without CNC. Once you’ve embraced CNC as your joint method, why wood is the next question. If you want to learn wood joints, learn mortise and tenon, dovetails, dowels or floating tenons, and nailed/screwed joints. Some extra love for biscuit miter joints but really that is all the main ones people use.